Given the path he’s taken after his 2014 US Open final appearance, it was hard to consider Kei Nishikori a serious contender for the title this year. But, he managed to outlast an out of sorts Andy Murray this afternoon in a tight five-setter. It looked early on that Murray was going to dominate, but an opportune rain delay helped Nishikori to collect himself, and an inopportune sound system malfunction caused Murray to lose his focus. Even so, when Nishikori lost his break lead in the final set, it seemed like Murray would manage to squeeze this one out, but a combination of errors from Murray and a few well-placed drop shots helped Nishikori close it out. As for Murray, it would be hard for him to complain about the season he’s had so far, but given the depleted field, he had a reasonable chance to grab another title here, so this one won’t go down easy.

2. Pliskova is the real deal.

One person who definitely doesn’t regret her summer schedule is Karolina Pliskova. Perhaps her win in Cincinnati gave her the confidence, and the poise, to make it past an overwhelmed Ana Konjuh to the semifinals. Whether she will be able to make inroads against Serena Williams depends largely on Serena’s form, but if she’s serving well, Pliskova will have her chances.

3. Serious Gael is a winning Gael.

Who knew that Gael Monfils isn’t keen on being known as a showman? This I find rather suspect, given his penchant for gratuitous leaping forehands. But, even without as many of his showstopping tricks, Monfils has put together an impressive season, and has a reasonable chance against Djokovic in the semifinals. The real question will be whether he will be able to stand up to the pressure of competing to make his first Grand Slam final against a very well rested Djokovic. But, as Monfils himself noted, even if Djokovic may be the better player, that doesn’t mean Monfils can’t win on the right day.

Once we got into the second set of the Serena Williams-Simona Halep quarterfinal on Wednesday night, Halep simply stopped missing. And for the better part of the set, she used her aggressive shotmaking to save a dozen break points and to break Serena’s serve. Serena seemed to blink a bit — more errors, more plaintive exclamations, and more hesitation in her shotmaking and her net approaches. But, Serena regrouped at the beginning of the third set, blasting returns past Halep as she had in the first set. And, Halep, for all of her effort in the second set, started to miss a bit. That was all Serena needed to get through, but Halep can be pleased with her effort in this match — the match-up was always going to be a huge challenge, but she certainly acquitted herself well.

5. Delpo is getting there, but there’s work to do.

Juan Martin del Potro’s run at the Olympics and to the US Open quarterfinals is nothing short of a dream for those who remember those sad days in between his wrist surgeries. The good news is that his forehand is as strong as ever. The bad news is that his backhand, while improving, it still a liability, and he has not yet ramped up enough to be effective in the latter stages of a best of five set match, especially at the business end of a tournament. But, it leaves him in good form for the indoor season, with its largely best of three format, and maybe with some time to continue to build his endurance. As for the backhand, if he can get in control of the point early, he can work around it, but otherwise, he’d better be prepared to do a lot more running than he used to. But, as always, it is an absolute pleasure to see him back in the mix.

As for Stan Wawrinka, the draw has opened up for him more than he could have expected at the start of the tournament. Meeting Delpo in the later rounds was an advantage, just because the Argentinean wasn’t as fresh as he would have been at the start of the US Open, particularly after the arduous run in Rio. But now, Stan has a very winnable match against Kei Nishikori to make the final against a maybe(?) injured Novak Djokovic. With Stan, nothing is predictable, but he’s been known to make the most of the big opportunities that have come his way.

6. I hope Novak doesn’t have a voodoo doll of me.

Five matches, three injured opponents. What a strange US Open for Novak Djokovic and those who have attempted to watch his matches. While some may say that missing matches affects his rhythm, I’d guess that he’s perfectly happy with his path to the semis. If I were Monfils, I’d be extra cautious right now.